Rohingya refugees line up to get food aid from a local NGO after arriving from Myanmar at the Balukali refugee camp in Cox's Bazar, Bangladesh. More than half a million Rohingya refugees have flooded into Bangladesh to flee an offensive by Myanmar's military that the United Nations has called "a textbook example of ethnic cleansing." The refugee population is expected to swell further, with thousands more Rohingya Muslims making the perilous journey on foot toward the border, or paying smugglers to take them across by water in wooden boats.

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Rohingya refugee boy cries as he fights his way in the crowd to get food aid from a local NGO at the Balukali refugee camp in Cox's Bazar, Bangladesh.

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A Rohingya refugee family uses a candle for light as they sit in a makeshift shelter n the roadside after fleeing their village in Myanmar in Cox's Bazar, Bangladesh.

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A Rohingya refugee girl wears a plastic bag as she walks in the monsoon rains at the Palongkali refugee camp on Sept. 19, 2017 in Cox's Bazar, Bangladesh.

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Rohingya refugees crowd as food is distributed by a local NGO near the Balukali refugee camp on Sept. 20, 2017 in Cox's Bazar, Bangladesh.

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A Rohingya refugee boy desperate for aid cries as he climbs on a truck distributing aid for a local NGO near the Balukali refugee camp on Sept. 20, 2017 in Cox's Bazar, Bangladesh.

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Rohingya refugees desperate for aid crowd as food is distributed by a local NGO near the Balukali refugee camp on Sept. 20, 2017 in Cox's Bazar, Bangladesh.

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A Rohingya refugee boy carries his belongings as he arrives with his family after crossing the Naf River at Shah Porir Dwip on Sept. 21, 2017 in Cox's Bazar, Bangladesh.

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Rohingya refugees rest in an Islamic school, or madrassa, after arriving by boat on the Bangladesh side of the Naf River at Shah Porir Dwip after fleeing their villages in Myanmar, on Sept. 22, 2017 in Cox's Bazar, Bangladesh.

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A cleric touches the head of a Rohingya refugee woman as she asks for food as they rest in an Islamic school, or madrassa, after arriving by boat on the Bangladesh side of the Naf River at Shah Porir Dwip after fleeing their villages in Myanmar, on Sept. 22, 2017 in Cox's Bazar, Bangladesh.

A Rohingya refugee man who was shot in the back by the Myanmar army is helped by a relative after crossing the border to the Bangladesh side of the Naf River while fleeing Myanmar, on Sept. 24, 2017 in Cox's Bazar, Bangladesh.

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Rohingya refugees sit in front of their makeshift shelters as other arrive carrying belongings at the Palongkali refugee camp on Sept. 24, 2017 in Cox's Bazar, Bangladesh.

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The Palingkali Rohingya refugee camp is seen at night on Sept. 24, 2017 in Cox's Bazar, Bangladesh.

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A Rohingya refugee woman collapses on her bags from exhaustion after arriving on the Bangladesh side of the Naf River from Myanmar on Sept. 25, 2017 in Cox's Bazar, Bangladesh.

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Rohingya refugees pray at the site where they are building a new mosque at the sprawling Balukali refugee camp on Sept. 25, 2017 in Cox's Bazar, Bangladesh.

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A Rohingya refugee washes at a well at the Palongkali refugee camp on Sept. 26, 2017 in Cox's Bazar, Bangladesh.

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Makeshift shelters are seen at the sprawling Balukali Rohingya refuge camp on Oct. 2, 2017 in Cox's Bazar, Bangladesh.

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A Rohingya refugee family reacts as they disembark from a boat after arriving on the Bangladesh side of the Naf River at night from Myanmar on Sept. 26, 2017 in Cox's Bazar, Bangladesh.

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Malnourished and suffering from diarrhea, two Rohingya refugee children cry on the floor of a makeshift shelter at the Balukali refugee camp on Sept. 27, 2017 in Cox's Bazar, Bangladesh.

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A Rohingya refugee woman holds her child as she stands outside her shelter at the sprawling Balukali refugee camp on Sept. 27, 2017 in Cox's Bazar, Bangladesh.

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Rohingya refugees carry their belongings as they walk through water on the Bangladesh side of the Naf River after fleeing their village in Myanmar, on Sept. 28, 2017 in Cox's Bazar, Bangladesh.

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A woman carries the body of a Rohingya refugee boy as others are seen wrapped in white sheets prior to burial after they died when their boat capsized while fleeing Myanmar on Sept. 29, 2017 in Cox's Bazar, Bangladesh.

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An Islamic cleric leads prayers for 16 Rohingya refugees who dies when their boat capsized while fleeing Myanmar during their funeral on Sept. 29, 2017 in Cox's Bazar, Bangladesh.

A Rohingya refugee woman is helped from a boat as she arrives exhausted on the Bangladesh side of the Naf River at Shah Porir Dwip after fleeing her village in Myanmar, on Oct. 1, 2017 in Cox's Bazar, Bangladesh.

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A Rohingya refugee woman sits exhausted after collapsing on a beach on the Bangladesh side of the Naf River at Shah Porir Dwip after fleeing her village in Myanmar, on Oct. 1, 2017 in Cox's Bazar, Bangladesh.

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A Rohingya refugee family carry their belongings as they walk on the Bangladesh side of the Naf River after arriving by boat from Myanmar at Shah Porir Dwip on Oct. 1, 2017 in Cox's Bazar, Bangladesh.

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A Rohingya refugee woman uses a candle to light her tent at the Palongkali refugee camp, on October 1, 2017 in Cox's Bazar, Bangladesh.

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A Rohingya refugee woman is carried by relatives near the border on the Bangladesh side of the Naf River after fleeing Myanmar, on Oct. 2, 2017 in Cox's Bazar, Bangladesh.

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A Rohingya refugee family rest as they sit on the ground on the Bangladesh side of the Naf River after fleeing Myanmar, on Oct. 2, 2017 in Cox's Bazar, Bangladesh.

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A Rohingya refugee woman suffering from malnutrition and diarrhea lays in the "Rohingya Ward" at Sader Hospital on Oct. 2, 2017 in Cox's Bazar, Bangladesh.